Which type of number is represented by decimals such as 0.4 and 12.273642 in C++?

Decimals such as 0.4 and 12.273642 in C++ are classified as floating-point numbers. Floating-point representation is designed to handle real numbers that require a decimal point, allowing for the inclusion of fractional components.

In C++, floating-point types include float, double, and long double. They are utilized to represent a wide range of values, including numbers with significant digits after the decimal point, which is essential for calculations that require precision in fractional values. The terms "float" and "double" refer to different levels of precision and range, with "double" providing more precision than "float".

In contrast, integer numbers lack decimal points and only express whole numbers, while long numbers extend the range of integers but still do not include decimal points. Character numbers are used to store single characters or strings of text, not numerical values. Therefore, floating-point numbers are the correct classification for the provided decimal examples.